The present invention is directed towards an improved arrangement for releasably locking a compressor in a selected position within a file drawer.
The present construction is similar to the structures described in U.S. Pat. Nos. 1,910,689 and 2,689,573 in that it employs latching elements associated with opposite ends of a compressor mounted metal rod to releasably lock the compressor against movements relatively towards the rear of the drawer, while permitting free movement of the compressor towards the front of such drawer.
More specifically, in U.S. Pat. No. 1,910,689, the compressor is in the form of a plate, which is supported to upstand from within a drawer and extend transversely between the side walls of such drawer by means of a pair of compressor mounted guide shoes sized to be slidably fitted one within each of a pair of facing, longitudinally extending channels formed by the side walls. The compressor is releasably locked in position within the drawer by latching means including a pair of wedge or cam members, which are fixed one to each of the guide shoes to extend rearwardly of the compressor one within each of the side wall channels, and latching elements, which are in the form of a pair of rollers freely journaled on stub shaft extensions of crank arms formed integrally with opposite ends of a compressor mounted metal rod and arranged within the side wall channels for releasable camming engagement with facing surfaces of the wedge members and channels. The metal rod is arranged to extend horizontally across the rear surface of the compressor intermediate the crank arms and has a centrally disposed portion thereof non-rotatably fixed to an operating member or handle. The operating member is supported within a pair of upwardly opening bearing notches, which are defined by compressor mounted, centrally disposed support flanges, for pivotal movements about a horizontal axis disposed vertically above the rod, whereby to effect unlocking and locking movements of the rollers, as the operating member is pivoted towards and away from the compressor, respectively. Opposite ends of the rod disposed relatively inwardly of the crank arms, are constrained for rotary/vertical reciprocating movements within aligned slot openings defined by compressor mounted, end guide flanges, and the mid-portion of the rod is constrained by the operating member support flanges for arcuate movements and to prevent removal of the operating member from within the bearing notches when the compressor is in use.
As a result of the above described construction, pivotal movement of the operating member towards the compressor into its release position is disclosed as imparting movement to the rod in two directions, namely, the rod is first turned or rotated about its axis by an amount corresponding to the angular displacement of the operating member, and the mid-portion of the rod is moved rearwardly away from the compressor by an amount determined by the angular displacement of the operating member. It is asserted that the turning movement of the rod serves to turn the crank arms sufficiently to move the rollers to an unlocked position, whereas the arcuate movement of a mid-portion of the rod away from the compressor serves to spring the rod sufficiently so that its tendency to assume its original position serves to rotate the crank arms in order to return the rollers to their locking position, as well as to return the operating member to its initial or rest position, when the operating member is released.
Upon study of the operational characteristics of the compressor latching arrangement disclosed in U.S. Pat. No. 1,910,689, it would appear that a drawback of such arrangement is the difficulty with which it can be assembled/disassembled relative to the compressor and/or the drawer, and the additional fabricating steps required by making the metal rod/operator member of multiple piece construction.
U.S. Pat. No. 2,689,573 discloses a compressor locking arrangement, which is comparable in construction and mode of operation to that described in U.S. Pat. No. 1,910,689, except that the latching elements are defined by the free ends of crank arm like members carried adjacent the ends of an operating rod and that such latching elements are arranged for engagement with serrations of locking slots defined by the side wall channels. As in an alternative construction described in U.S. Pat. No. 1,910,689, a separate spring device is employed to bias the rod for rotation in order to normally retain the locking elements in their locking position.